1. Field of the Invention
This invention relates to fasting devices. More particularly, this invention relates to fastening devices for fastening together a multilayered workpiece in which the fastening device receives therein a thermo-setting material, the device being secured within a plurality of apertures defined by a multi-layered workpiece or the like.
2. Information Disclosure Statement
A common source of failure of conventional metallic fasteners is caused by the vibration or movement between the metallic fastening device and the metallic workpiece. This movement results in fatiguing and the wear of the metallic fastening device which enables further movement resulting in further deterioration of the fastening device. Various types of means and methods have been provided in the prior art for eliminating this undesired movement between a metallic fastening device and a metallic workpiece.
Some examples of patents which are pertinent to the instant invention include U.S. Pat. Nos. 207,871, 2,408,559, 2,410,398, 2,417,262, 2,453,994, 2568,075, 2,677,149, 2,928,446, 2,989,107, 3,362,276, 3,293,977, 4,088,327, 4,140,742, 4,163,812, 4,183,974 and 4,189,369.
Although these prior art patents have solved some of the needs of the prior art, none of these patents have successfully provided a simple and efficient fastening device for securing within an aperture of a workpiece for reducing the undesired movement therebetween.
Particularly in the aircraft industry, it has been customary to rivet juxtaposed plates together. These prior art rivets have often included a head portion protruding from the smooth surface of the plate being riveted. Such protruding heads not only detract from the aesthetic appearance of the aircraft, but more particularly present a resistance to air flow resulting in increased fuel costs and a reduction in maximum relative speed of the aircraft.
Although in the prior art various proposals have been disclosed for blind riveting aircraft plates having countersunk heads, these prior art proposals have necessitated the employment of relatively complex riveting equipment. Furthermore, a need has existed in the art for flexibly bonding together adjacent plates in the aircraft industry because it has been found that such flexible bonding reduces the amount of metal fatigue that has been associated with the prior art riveted plates.
The present invention provides a fastening device which enables a plurality of metal plates or lamina to be flexibly bonded together by means of a plurality of elongate members which define channels for the insertion therein of a thermo-setting resin or the like such that there is a clearance between the elongate members and the metal plates, the clearance being filled with the resin.
Therefore it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution of the advancement of the fastening art.
Another object of this invention is to provide a fastening device for securing within aperture of a workpiece having a groove disposed along a longitudinally extending body member of the fastening device for receiving a resilient material within the groove for co-acting between the body member and the workpiece for reducing undesired movement thereby.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece incorporating a thermal liquifying material within the groove to seal the fastening device to the workpiece upon the application of heat.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece including a thermal expandable material disposed within the groove of the fastening device to seal the fastening device to the workpiece upon the application of heat.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece wherein a resilient material is injected between the fastening device and the workpiece after insertion of the fastening device into the aperture of the workpiece.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece including an aperture extending through a fastener head of the fastening device and in fluid communication with the grooves extending along a longitudinally extending body member of the workpiece enabling a resilient material to be introduced through the fastening head aperture to fill the groove and region between the fastening device and the workpiece to reduce vibration therebetween, the resilient material being disposed between the workpiece and the fastening device such that the workpiece does not contact the fastening device.
Another object of this invention is to provide a method of installing a rivet into an aperture of a workpiece by inserting the rivet into the aperture of the workpiece and deforming the rivet into the aperture of the workpiece and subsequently injecting a resilient material through a head aperture in the rivet to resiliently engage the rivet to the workpiece.
Another object of the present invention is to provide a fastening device for fastening together a multi-layered workpiece that overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which significantly contributes to the reduction in wind resistance of the fastened workpiece and the inhibition of metal fatigue.
Another object of the present invention is the provision of a fastening device for the reception therein of a thermo-setting material in which the thermo-setting material is injected within a channel extending through the fastening device such that the thermo-setting material fills the interstices between the multi-layers of the workpiece and the fastening device.
Another object of the present invention is the provision of a fastening device which includes a first lamina member which defines a plurality of transverse bores each of which are aligned with an aperture of the plurality of apertures defined by the multi-layered workpiece and a plurality of elongate members secured to the first lamina member and extending through the respective apertures such that the thermo-setting resin flows along an internal channel of the elongate member to fill the interstices between the multi-layers and the elongate members.
Another object of the present invention is the provision of a fastening device in which the channel extends from a first end of the elongate member towards the second end thereof and a plurality of lateral holes radiate from the longitudinal channel to the outer surface of the elongate member such that the thermo-setting material flows through the channel and through the lateral holes to fill the interstices between the apertures and the elongate members.
Another object of the present invention is the provision of a fastening device in which the first lamina member is planar and includes a sprue and a plurality of radially extending passages defined by the first lamina member such that each of the passages extends radially from the sprue to one of the channels so that the thermo-setting material is injected through the sprue and flows along each of the passages and along each of the channels and holes to fill interstices between the plurality of apertures and the elongate members for fastening the layers of the workpiece together.
Another object of the present invention is the provision of a fastening device in which the elongate members each further include a plurality of annular grooves, each of the grooves being located along the length of the elongate member such that material flowing laterally out of the holes flows around the grooves before flowing into the interstices between the plurality of apertures and the elongate members within the apertures.
Another object of the present invention is the provision of a fastening device including a second lamina member which defines a second plurality of transverse bores each of which are aligned with an aperture of the plurality of apertures defined by the workpiece such that the second ends of each of the plurality of elongate members are secured within a bore of the second plurality of bores when the elongate members extend through the workpiece.
Another object of the present invention is the provision of a fastening device in which at least some of the lateral holes terminate within the bores of the second plurality of bores such that a portion of the thermo-setting material fills the interstices between the second end of each of the elongate members and the bores of the second lamina member.
Another object of the present invention is the provision of a method of fastening together a plurality of layers of a workpiece. The method includes clamping the first lamina member against the workpiece and drilling a plurality of bores therethrough, inserting the elongate members within the bores of the first lamina member, inserting the second ends of the elongate members within the apertures formed in the workpiece and injecting thermo-setting material into the longitudinal channels to fill the interstices between the apertures of the workpiece and the elongate members such that the workpiece and elongate members are spaced relative to each other by the thermo-setting material.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a further understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.